Technical Field
The present disclosure relates to a semiconductor device and a cell voltage equalization method for battery cells.
Related Art
Japanese Patent Application Laid-Open (JP-A) No. JP 2002-325370 discloses a charge state control section including plural battery cells connected in series and plural resistance elements connected in series. The charge state control section compares a voltage of each battery cell with a voltage divided by the resistance elements. Further, based on the result of the comparison, the charge state control section discharges a battery cell that has a voltage exceeding an allowable range of ideal voltage values, and equalizes the cell voltage of each of the battery cells.
In the technique that uses plural battery cells described above, the cell voltage of the battery cells are measured so as to prevent over-discharge or over-charge of the battery cells. Meanwhile, recently, miniaturization in semiconductor devices are advancing, and micronization in integrated circuit (IC) chip for use in the semiconductor devices are required.
However, in the technique described in JP-A 2002-325370, since a group voltage detection circuit measures a total voltage of the battery cells connected in series, high voltage resistant elements are used in the semiconductor element that configure the group voltage detection circuit. As a result, the size of the IC chip increases and cost of the IC chip increases.